1. Field of the Invention
The present invention relates to an apparatus for an artificial kidney for continuously measuring a component in body fluid such as blood or plasma, or liquid for treatment such as dialyzing fluid or supplementary liquid, or for measuring it and further adjusting the partial pressure of oxygen in the body fluid or in the liquid for treatment using oxygen supplying means, to a fluid circuit used in such an apparatus, and a quality evaluating device using such an apparatus for artificial kidney and its fluid circuit.
The present invention also relates to a method of preventing or treating hypotension and hypoxia associating with artificial dialysis in treatment using an apparatus for an artificial kidney by controlling partial pressure of oxygen in body fluid.
2. Description of the Related Art
Abnormal living body cases of an artificial dialysis patient include hypotension in dialysis (Mariko Kato, Journal of Japanese Society of Nephrology, Vol. 29, pp. 1249-1259 (1987)), hypoxia in dialysis where the partial pressure of oxygen in artery is decreased (Takumi Okamoto, Medical Journal of Hiroshima University, Vol. 35, pp. 1031-1081 (1987) and Jacob A. J. et al., Kidney International, Vol. 18, pp. 505-509 (1980)), and the like. It has been pointed out that decrease in the partial pressure of oxygen in the blood during dialysis (hereinafter referred to as P02) is part of the onset mechanism of the hypotension in dialysis that previously described in literatures. Recently, it has been pointed out that, during dialysis, a large amount of nitric oxide (hereinafter referred to as NO) having a strong vasodilator action is produced in the blood through the stimulus of cytokine, endotoxin, or the like, which participates in the onset mechanism of the hypotension in dialysis.
For example, it is reported that, during hemodialysis, the concentration of NO and NO oxydants (hereinafter referred to as NOx) is increased, and thus, acceleration of NO production in dialysis patients is observed (Nobuo Oyama et al., Journal of Japanese Society for Dialysis Therapy, Vol. 29, pp. 29-35 (1996), Hiroe Nakazawa et al., Chiryogaku (Biomedicine and Therapeutics), Vol. 24, pp. 283-287 (1996), Masato Nishimura et al., Therapeutic Research, Vol. 18, pp. 2205-2209 (1997), Fukuyama N. et al., Free Radical Biological Methods, Vol. 22, pp. 771-774 (1997), Nobuo Oyama et al., Jin to Toseki (Kidney and Dialysis), Vol. 45, pp. 765-768 (1988), Tetsuo Unno, Journal of Japanese Society for Dialysis Therapy, Vol. 31, pp. 933-938 (1998), Ellen S. et al., American Journal of the Medical Sciences, Vol. 313, pp. 138-146 (1997), Madore F. et al., American Journal of Kidney Diseases, Vol. 30, pp. 665-671 (1997), and Douma C. E. et al., Advance in Peritoneal Dialysis, Vol. 11, pp. 36-40 (1995)). NO has physiological functions such as a strong vasodilator action. Chemically, at a high concentration, oxidation reaction of NO is rapid, while, at a steady state in blood (0.1-10 xcexcM), NO is relatively stable (Takashi Yonetani, Folia Pharmacologica Japonica, Vol. 112, pp. 155-160 (1998)).
Attempts to prevent hypoxia during hemodialysis include a case where sodium bicarbonate dialyzing fluid having high partial pressure of carbon dioxide (PCO2) is used instead of acetic acid dialyzing fluid (Hideo Igarashi, Japanese Journal of Thotacic Diseases, Vol. 24, pp. 531-540 (1986)) and a case where pharmacotherapy is used (Hitoshi Masuda, et al., Japanese Journal of Clinical Medicine, Vol. 49, 1991, Special Issue, Blood Purification (the first volume), pp. 709-713), and the like. With regard to determination of NO described in the above-described publicly known literature, an indirect method which presumes the amount of NO from the amount of NOx produced, for example, the Griess method (Green L. C. et al., Analytical Biochemistry, Vol. 126, pp. 131-138 (1982) has been generally used.
To evaluate biocompatibility of a hemodialyzer using a hollow fiber membrane, a method with the amount of NO or NOx produced being an index has been conventionally reviewed. Such a method measures the amount in vitro using blood sampled intermittently (Nobuhiro Sasaki et al., Journal of The Japanese Society for Dialysis Therapy, Vol. 32, pp. 363-368 (1999), Rysz J. et al., Kidney International, Vol. 51, pp. 294-300 (1997), and Amore A. et al., The Journal of American Society of Nephrology, Vol. 6, pp. 1278-1283 (1995)). In these methods, since continuous measurement is not possible, change during hemodialysis can not be known immediately.
A method of measuring PO2, PCO2, or pH in blood passing through an extracorporeal circulation circuit using the electrode method is disclosed in, for example, JP-A-61-2867, JP-A-61-280844, JP-A-62-155834, JP-A-62-270136, JP-A-64-50948, JP-A-9-10300, JP-A-9-10301, JP-A-3-131240, and JP-A-9-19497. As an example of measurement of NO concentration in vivo using an NO electrode, there is a case of cardiac muscle tissue of a rabbit under anesthesia where NO concentration and partial pressure of oxygen in artery are simultaneously measured (Seiichi Kato, The Journal of Japanese Dental Society of Anesthesiology, Vol. 25, pp. 184-196 (1997). However, no case is known where such measurement is applied to an apparatus for an artificial kidney and to a fluid circuit.
In view of the above, the present invention is made to solve the problem of participation of NO in dialysis induced hypotension, hypoxia in dialysis, and the like during artificial dialysis, and an object of the present invention is to provide an apparatus which can continuously monitor fluctuation in a gaseous component, an ionic component, or the like in body fluid such as blood and can suppress these diseases. Another object of the present invention is to provide quality evaluating means of an artificial dialyzer and dialyzing fluid using such an apparatus.
The inventors of the present invention vigorously carried out researches to solve the above-described problem, and found that to continuously measure the nitric oxide concentration in the blood circulation circuit or the dialyzing fluid circuit during dialysis, is useful to prevent hypotension in dialysis. Further, the inventors of the present invention found that, by maintaining PO2 in a normal range, the partial pressure of oxygen in arterial blood during dialysis, excess increase in the NO concentration in blood pointed out as participating in dialysis induced hypotension can be prevented. Further, the inventors of the present invention found that oxygen supply to arterial blood is effective in facilitating metabolism of NO in blood and in suppressing hypoxia.
The present invention is implemented by the following structures.
(1) An apparatus for an artificial kidney comprising a first fluid circuit for introducing body fluid into dialyzing means, dialyzing means for removing waste products from the body fluid, and a second fluid circuit for recovering the body fluid, further comprising a measurement monitor for continuously measuring at least one component of the body fluid in the first fluid circuit and/or the second fluid circuit.
(2) An apparatus for an artificial kidney as described in the above (1), wherein the component is at least one which is selected from a group consisting of nitric oxide, oxygen, nitrous acid ions, and nitric acid ions.
(3) An apparatus for an artificial kidney as described in the above (1) or (2), wherein at least one which is selected from a group consisting of the first fluid circuit, the dialyzing means, and the second fluid circuit is provided with a treatment liquid supplying device for supplying liquid for treatment.
(4) An apparatus for an artificial kidney as described in any one of the above (1) to (3), further comprising oxygen supplying means for increasing partial pressure of oxygen in arterial blood of a living body.
(5) An apparatus for an artificial kidney as described in the above (4) comprising a first fluid circuit for introducing body fluid of a living body into dialyzing means, dialyzing means for removing waste products from the body fluid, a second fluid circuit for recovering and returning the body fluid to the living body, and oxygen supplying means for increasing partial pressure of oxygen in arterial blood of the living body, characterized by further comprising a measurement monitor for continuously measuring at least one component of the body fluid in the first fluid circuit and/or the second fluid circuit, and display means for displaying the result of comparison between a measurement value measured by the measurement monitor and a desired value.
(6) An apparatus for an artificial kidney as described in the above (5), wherein the apparatus controls, linked with the display by the display means, controls the oxygen supplying means and controls the partial pressure of oxygen in the body fluid or the liquid for treatment.
(7) A method for preventing or treating hypotension and/or hypoxia associated with artificial dialysis by comprising a first fluid circuit for introducing body fluid of a living body into dialyzing means, dialyzing means for removing waste products from the body fluid, a second fluid circuit for recovering and returning the body fluid to the living body, and oxygen supplying means for increasing partial pressure of oxygen in arterial blood of the living body, by further comprising a measurement monitor for continuously measuring at least one component of the body fluid in the first fluid circuit and/or the second fluid circuit, by comparing a measurement value measured by the measurement monitor with a desired value, and by controlling the concentration of the component of the living body.
(8) An apparatus for an artificial kidney as described in any one of the above (5) to (7), wherein the oxygen supplying means is at least one which is selected from a group consisting of an air bubble type oxygenator, a membrane type oxygenator, an oxygen inhaler, an oxygen tent, an oxygen respiration synchronizer, and an oxygen concentrator.
(9) An apparatus for an artificial kidney as described in any one of the above (1) to (8), wherein the dialyzing means is a blood processor using a hollow fiber membrane and/or the liquid for treatment is dialyzing fluid.
(10) A quality evaluating device for dialyzing means comprising a first fluid circuit for introducing body fluid into dialyzing means, dialyzing means for removing waste products from the body fluid, and a second fluid circuit for recovering the body fluid, further comprising a measurement monitor for continuously measuring at least one component of the body fluid in the first fluid circuit and/or the second fluid circuit, and optional oxygen supplying means, and capable of evaluating the quality of the dialyzing means.
(11) A fluid circuit usable in an apparatus for an artificial kidney as described in any one of the above (1) to (10), comprising a measurement monitor for continuously measuring at least one component of the body fluid in the fluid circuits, and/or oxygen supplying means.
(12) A quality evaluating device for dialyzing fluid comprising a first fluid circuit for introducing body fluid into dialyzing means, dialyzing means for removing waste products from the body fluid, and a second fluid circuit for recovering the body fluid, further comprising a measurement monitor for continuously measuring at least one component of the body fluid in the first fluid circuit and/or the second fluid circuit, optional oxygen supplying means, and a dialyzing fluid supplying device for supplying dialyzing fluid to the dialyzing means, and capable of evaluating the quality of the dialyzing fluid.
(13) A method of controlling the concentration of a component of body fluid of a living body by comprising a first fluid circuit for introducing body fluid of a living body into dialyzing means, dialyzing means for removing waste products from the body fluid, a second fluid circuit for recovering and returning the body fluid to the living body, and oxygen supplying means for increasing partial pressure of oxygen in arterial blood of the living body, by further comprising a measurement monitor for continuously measuring at least one component of the body fluid in the first fluid circuit and/or the second fluid circuit, and by comparing a measurement value measured by the measurement monitor with a desired value.
(14) A method as described in any one of the above (10) to (13), wherein the oxygen supplying means is at least one which is selected from a group consisting of an air bubble type oxygenator, a membrane type oxygenator, an oxygen inhaler, an oxygen tent, an oxygen respiration synchronizer, and an oxygen concentrator.
(15) A dialyzing fluid supplying device comprising a third fluid circuit for introducing dialyzing fluid, and a fourth fluid circuit for recovering the dialyzing fluid, characterized by further comprising a measurement monitor for continuously measuring at least one component of the dialyzing fluid in the third fluid circuit and/or the fourth fluid circuit.
In the above (15), it is the apparatus for an artificial kidney as described in the above (1) which comprises the third fluid circuit for introducing the dialyzing fluid, and the third fluid circuit for introducing dialyzing fluid is a dialyzing fluid supplying circuit for supplying dialyzing fluid to the dialyzing means. The fourth fluid circuit may be a dialyzing fluid recovering circuit for recovering the dialyzing fluid from the dialyzing means. Further, in the above (15), the third fluid circuit for introducing the dialyzing fluid may be a peritoneal dialyzing fluid introducing circuit for introducing the dialyzing fluid to the abdominal cavity and dialyzing blood in capillaries in the peritoneum utilizing the peritoneum in peritoneal dialysis, and the fourth fluid circuit may be a peritoneal dialyzing fluid drain circuit for collecting waste products from the inside of the abdominal cavity to the outside of the body.
(16) An apparatus for an artificial kidney comprising a measurement monitor for continuously measuring nitric oxide as a component of body fluid or liquid for treatment.
(17) An apparatus for an artificial kidney comprising a measurement monitor for continuously measuring a component of body fluid or liquid for treatment, a display means for comparing a measurement value measured by the measurement monitor with a control value, and when the measurement equals the control value, displays the equality, and oxygen supplying means.
(18) An apparatus for an artificial kidney as described in the above (16) or (17), wherein the component is at least nitric oxide and oxygen.
(19) An apparatus for an artificial kidney as described in any of the above (16) to (18), wherein the component is at least one selected from a group consisting of, in addition to the above, nitrous acid ions, nitric acid ions, and carbonic acid ions.
(20) An apparatus for an artificial kidney as described in any one of the above (17) to (19), wherein the apparatus controls, linked with the display by the display means, controls the oxygen supplying means, and controls the partial pressure of oxygen in the body fluid or the liquid for treatment.
(21) An apparatus for an artificial kidney as described in any one of the above (17) to (20), wherein the oxygen supplying means is an oxygen inhaler or an oxygenator to the body fluid or an oxygen addition to the liquid for treatment.
(22) An apparatus for an artificial kidney as described in any one of the above (16) to (21), wherein the artificial kidney is a blood processor using a hollow fiber membrane.
(23) A quality evaluating device for evaluating the quality of a blood processor using a hollow fiber membrane which uses an apparatus for an artificial kidney as described in any one of the above (16) to (22).
(24) A quality evaluating device for evaluating the quality of dialyzing fluid as liquid for treatment which uses an apparatus for an artificial kidney as described in any one of the above (16) to (22).
(25) A fluid circuit for an apparatus for an artificial kidney comprising a nitric oxide measuring portion for continuously measuring nitric oxide as a component of body fluid or liquid for treatment.
(26) A fluid circuit for an apparatus for an artificial kidney comprising a component measuring portion for continuously measuring a component of body fluid or liquid for treatment, and an oxygen adding portion for adding oxygen to the body fluid or the liquid for treatment.
(27) A fluid circuit for an apparatus for an artificial kidney as described in the above (25) or (26), wherein the component is at least nitric oxide and oxygen.
(28) A fluid circuit for an apparatus for an artificial kidney as described in any one of the above (25) to (27), wherein the component is at least one selected from a group consisting of, in addition to the above, nitrous acid ions, nitric acid ions, and carbonic acid ions.
(29) A fluid circuit for an apparatus for an artificial kidney as described in any one of the above (25) to (28), wherein the artificial kidney is a blood processor using a hollow fiber membrane.
(30) A circuit for a quality evaluating device for evaluating the quality of a blood processor using a hollow fiber membrane which uses a fluid circuit as described in any one of the above (25) to (29).
(31) A circuit for a quality evaluating device for evaluating the quality of dialyzing fluid as liquid for treatment which uses a fluid circuit as described in any of the above (25) to (29).